Fire box for steam generators



- v 1,640,346 1927' s. A. BRYAN FIRE BOX FOR STEAM GENERATORS Filed June8 1921 2 Sheets-Sheet l O O O M I NV EN TOR.

ATTORNEYS.

Aug. 30, 1927.

G. A. BRYAN FIRE BOX FOR STEAM GENERATORS Filed June 8. 1921 2Sheets-Sheet 2 QV IIAIIM' WIIIMIIIIIIIII INi ENTOR.

BY I

' ATTORNEYS.

Patented Aug. 30, 1927.

UNITED STATES PATENT OFFICE.

eEoRGE ALERED BRYAN, oE rERn, INDIANA, AssIeNoR To BRYAN EARVESTER co!-EANY, A CORPORATION on NEW MEXICO.

EIRE FBOX EoR STEAM GENERATORS.

Application flied an a,

My invention relates to steam generating devices and particularly tosmall units burn-' ing liquid fuel and adaptable for use on .self

' fpropelled vehicles .such as tractors, trucks,

5 automobiles and the, like. More especially .my invention relates tothe fireboxesor furnaces of such devices.

- liquid fuel firing systems commonly used with small boilers, theburners are directly under the boiler and. the comparatively cold boilerwalls and tubes form the major porition of nace.

the combustion chamber of the fur- The resultis inefliciency andincomplete combustion. As the combustible mixture contacts with the coldsurfaces oxidation is retarded or stopped and large depositsof carbon onthe tubes result.

In accordance with my invention the fuel is completely consumed beforeany of .the gases of combustion reach the boiler. The furnace isarrangedexteriorly of the boiler liOtISlIl" and communicates with thesame at' or near the bottom which is preferably inclined upwardly from'the communicating opening to cause an equal distribution of the. gasesover the tubes'of the boiler. I The furnace is preferably vertical andis of the proper height and shape to give the bestrate of combustion.The height depends upon the pressure at which the fuel is delivered butis properly proportioned to cause all of the fuel to be consumed withinthecombus-tionchama her and before the gases reach the boiler.

Surmounting the combustion chamber in the pr eferred form is a mixingchamber through the top of which enters the spray nozzle at thisatomized fuel. I My invention also for the fuel, andthe air is furnishedpoint and thorou-ghlymixed with the the operation. The height anddiameter of contemplates various other features of construction andarrangements and combinations, of parts as will hereinafter more fullyappear.

I sha The boiler 1 may be of any suitable type, .but for the purpose ofillustration I have this boiler has an open bottom and the gases isinclined upwardly for a portion of its 1921. Serial N0. 475,989.

point out my invention in claims; Fig. 1 is a side elevation of acomplete unit embodying my invention. I V I Fig. 2 is a longitudinalsectional elevation of the fire box. 1

Fig. 3 is a rear elevation of the same. Fig. '4 is a horizontal sectionof thesame on line-4 -4 of Figure .3." I i j v Fig. 5 is an enlargedsectional detail of a fragmentof a side wall. i

shown a water tube boiler of the 'consjtruction disclosed in my co-pending application Serial No. 339,945., which became Patent No.1,497,973, June 17, 1924. The housing'for from the furnace or fire boxare delivered to this open bottom. j i

The fire box is of the down draft type, and comprises an uprightcombustion chamber 2 above which is the mixing chamber 3. The mixingchamber is shown as round in cross section, and the combustionchamberflares outwardly in its transverse dimension toward the bottom, whereitis ofoblong shape 7 to make proper connection with the boiler.

' The combustion chamber is entirely unobstructed and has at its bottomin the side next the boiler, an opening or passageway 4 for the hotgases of combustion; The bottom of the combustion chamber has anextension 5 underneath the boiler which completes the housing for theboiler. "This bottom 5 length to effect an even distribution of thegases over the tubes of the boiler.

JThe fuel is injected into the top of the mixing chamber in theform of afine spray and is there mixed with air, the combustible mixture beingignited at the initiation of the combustion chamber are determined b thepressure at whichthe fuel is delivere and are in every instance suchthat the fuel is completely burned by the time the gases U reach thepassage 4.

against the inner The walls of the combustion chamber of the fire boxare constructed of an outer thin ly projecting prongs or lugs which arestruck up from the material of the bands.

, These prongs serve as holding means for the fire clay, which may beapplied in a green state and afterwards burned into a high grade firebrick. These prongs also serve to reinforce the material 8 and enableitto withstand the vibrations to which the vehicle will be subjected. VI

Sui-mounting the combustion chamber and forming the mixing chamber .2is'a dome,,10 of sheet metal, the lower edge of which is secured in anysuitable manner to the top of the walls of the combustion cham ,ber. Asuitable spray nozzle 11 for the fuel Y enters the closed top of thisdome 10, being supported in place by a lug 12 on top of the dome.Surrounding the inner end of the I nozzle 11 is a conical baffle orshield 13 for the atomized fuel which extends down substantially to thebottom of the mixing chamber and iscut out at its two sides as shown.The air is delivered by a fan 14 against the face of this baflie 13intermediate the cut-out portions. The initial lighting of thecombustible mixture may beclone in any suitable way, as by a pilot lightora'match, or, as in the illustrated construction, by a spark plug 15.The details-of this atomizmg and mixing construction form the sub ectmatter of, my co-pending application Serial Number 478,682, filed June18, 1921,

a (Patent No. 1, 5262,26 1, dated July 17, 1923). The walls of thecombustion chamber become thoroughly heated in a short time after i theburner. is started and these Walls will retain their heat for aconsiderable period mixture. off e ther manually or'rautomatlcally whenof time and serve to ignite the combustible The fuel may therefore beshut the requisite steam pressure is obtained and again turned on as thepressure beginsto ual heat in the walls of the fire box.

fall, the -mixture being ignited by the resid-' Any jsuitable automaticcontrol system for the fuel pump and fan may be employed, for nstance,that illustrated in my prior Patent git-1,316,680, dated September 28,1919.

It will be noted that the furnace is so constructed that it has noarches or overhanging walls of refractory material commonly found inthis type of furnace. The delivery of the fuel through a nozzle in thetop of the mixing chamber is a feature of safety in that any drippinfrom the nozzle after the fuel is turned off falls to the bottom of thefurnace where it is instantly? flashed into a gas by the hot wall or issubsequently burned when the burner is again ignited When the furnace isproperly handled all danger from explosions due to gas or oil coming incontact with surfaces that cool them to such an extent that they cannotbe burned, is eliminated. I Tests have shown that any grade of liquidfuel may be burned in my furnace, from a very low grade distillate to.the higher grades of kerosene or motor fuel.

It is obvlous that various modificat ons may be made'in theconstructionshown inthe drawings and above particularly described,within the principle and scope of.

my invention.

I claim:

1; In combination with a steamgenerator including a boiler andahousing'therefor, a fire box exterior of the housing and communicatingtherewith and having a Com bllStlOIl chamber comprising a sheet metalouter casing, heat insulating material lining the sheet metalcasing,fand refractory material covering the heat insulating materialand applied in a continuous layer while in a plastic condition. g

2. In combination with a steam generator including a boiler. and ahousing therefor, a fire box exterior of the housing and communicatingtherewith and having a combustion chamber comprising a sheet metal outercasing, heat insulating material lining the sheet metal casing, bands ofsheet material having inwardly projecting prongs or lugs and disposedagainst the heat insulating material, and secured thereto by devicespassin throughv the heat insulating material. and th t;

metal casing, and a layer of refractory materlal coverlng the heatlnsulating materlal and secured and reinforced by the prongsor lugs onthe bands.

3.1n combination with a steam generator including a boiler and a housingtherefor, a fire box exterior of the housing ,and communicatingtherewith and having a combustion chamber comprising a sheet metal outercasing, heat insulating material lining the sheet metal casing, bands ofsheet material 'having inwardly projectingfprongs'or lugs and disposedagainst the heat insulating material and secured thereto by devicespasslng through the heat insulating material and the metal casing, alayer of refractory .material covering the heat insulating material andsecured and reinforced by the prongs or lugs on the hands; a mixingchamber surmounting the combustion chamber,

and means for delivering atomized liquid fuel and an oxidizing fluid tothe mixing chamber.

4. In combination with a steam generator including a boiler and ahousing one end of which has near its bottom an opening for theadmission of gases, and the bottom of which is inclined upwardly fromsaid opening, a fire box comprising a vertical combustion chambercommunicating at its bot- 10 tom directly with the said opening in thehousing, a mixing chamber surmounting the combustion chamber, andatomizing mechanism for liquid fuel in said mixing chamber.

In Witness whereof, I hereunto subscribe 1 my signature.

GEORGE ALFRED BRYAN.

